With the advent of tufting equipment, floor covering evolved over time from woven carpets to the tufted carpets in use today. Machine tufting began with a single needle, which was similar to a sewing machine. As shown in FIG. 1, a needle 1000 carries a yarn 104 through a primary backing substrate 120, which forms a stitch 112 on the back side adjacent the primary backing substrate 120. On the face side, a looper 1002 holds the yarn 104 to a specified height above the primary backing substrate 120 to form the pile 110 of the carpet. The tufted yarns 110 and the primary backing substrate 120 collectively may be referred to herein as a tufted textile substrate 114.
The single needle configuration progressed eventually to multiple needles operating side-by-side, which is how tufted carpets are made currently. Tufting widths of up to sixteen feet are possible with this equipment, and, when sold at these widths, these carpets are referred to in the industry as “broadloom” carpets. This type of carpet is the preferred flooring material for approximately 90% of residential homes and commercial buildings.
Initially, as the technology to produce broadloom carpet advanced, the only available primary backing substrate 118 was a woven jute material. As a natural fiber, jute is prone to expansion and contraction. Consequently, manufacturers began the practice of coating the jute primary backing substrate 118 with a water-based adhesive 130 and then attaching a secondary backing substrate 140 to form a tufted broadloom carpet 100, as shown in FIG. 2.
Broadloom carpets were traditionally installed in small residential rooms by stretching the carpet over a pad or cushion and attaching the stretched carpet to tack strips attached along the wall (as shown in FIG. 18). Over time and especially with moisture, the jute backing expanded and contracted, causing the carpet to wrinkle or pull off the pins. Further, it was found that the secondary backing could delaminate from the primary textile layer, when the carpet was exposed to wet conditions or stress loadings from foot traffic over the cushion. Although manufacturers began to recognize the need for increased stability in the carpet backings, many of these problems persisted until the introduction of synthetic primary and secondary backings, which reduced, but which did not totally solve, the previously mentioned growth problems.
In preparing to install the broadloom carpet 100, it was often necessary to tape the seams together to obtain a piece of carpet with the desired dimensions. Taping the seams was time-consuming, because the seam tapes included a hot-melt adhesive that must be heated upon application to the carpet to form a joint between adjacent carpet panels. In addition to the difficulties in aligning the adjacent carpet pieces with the seaming tape without wrinkling, the heating of the seam adhesive sometimes caused shrinkage in the secondary backing, especially since the secondary backing was made from a synthetic material. As a result, the seams could buckle, making the installation more difficult. This seam taping procedure for broadloom carpet installations continues to the present time.
About forty years ago, modular carpet products (that is, carpet tiles) were introduced to address some of the problems encountered with the broadloom carpet product described above. Initially, manufacturers attempted to simply cut existing broadloom constructions into modular units. Manufacturers also attempted to create modular products by applying thick polymer layers (without stabilization) to the back of a textile substrate. The primary issue experienced with these attempts was insufficient stability. When these initial product offerings failed, total replacement of the floor covering was required, leading to loss of customer confidence, loss of future sales, and incursion of significant financial loss for the manufacturers.
These initial modular carpets were created using a bonded broadloom product, rather than a tufted carpet. A bonded carpet 200 is made by physically adhering the face yarns 205 to the face side of a primary bonding substrate (150) using a polyvinyl chloride (PVC) adhesive 132, as shown in FIG. 3. Again, woven jute was the first material used as the primary bonding substrate (150) in the bonded carpet 200. As the technology progressed, the jute substrate was replaced with a synthetic bonding substrate 150 to overcome the stability problems discussed above. A heavyweight backing 160 made of polyvinyl chloride was applied directly to the back side of the primary bonding substrate 150 (without a separate reinforcement layer), which permitted the carpet 200 to be cut into individual tiles that could be installed without adhesive (leading manufacturers to coin the term “free lay”).
It was required that modular carpet tiles possess sufficient stability to remain in their installed positions on the floor and to remain flat without the edges rising (a phenomenon known as “curling”) and without the center rising (known as “cupping”). To meet these objectives, the tiles were typically installed with a grid pattern of adhesive applied to the floor along the perimeters of the tiles. In addition, it was expected that the modular carpet construction would exhibit a high level of dimensional stability and not shrink or expand under use.
Because individual tiles of an installation can be removed and replaced when soiled or worn, modular carpets were useful in applications where broadloom carpets were impractical, such as offices, airports, and other high-traffic areas. The ease with which carpet tiles could be removed proved especially advantageous in facilities with under-floor wiring or HVAC equipment.
While the commercial market enthusiasm for a modular flooring product was even greater than that for broadloom carpets, the initial modular product proved insufficient to meet the needs of the environments in which it was installed. Specifically, as time passed, plasticizers used in the PVC backing (160) began to migrate from the backing layer, causing the backing layer (160) to change in dimension. The tiles began to experience cupping, in which the face side of the carpet tile has a greater dimension than the backing layer and the middle of the carpet tile rises above the floor.
As shown in FIG. 4, the next advancement led to the production of a bonded carpet tile 202 with a dense cut pile 205 and with greater stability. The dense cut pile 205 had no texture imparted to the yarns. To increase the stability of the tile 202, a pre-formed mat of fiberglass 170 replaced the synthetic primary backing substrate 120 (as the surface to which the pile yarns 205 were adhered), and a second mat of fiberglass 175 was embedded between PVC backing layers 160, 165. The “I-beam” construction created by the PVC backing layers 160, 165 and the fiberglass mat 175 prevented the PVC backing layers 160, 165 from shrinking and formed a rigid, fairly inflexible structure. The carpet tiles 202 had to be stacked and boxed for shipping, rather than being rolled onto a tube as was the conventional shipping method for broadloom carpets. An additional issue with manufacturing the carpet tiles 202 was that the critical positioning of the fiberglass 175 between the PVC backing layers 160, 165 required specialized equipment. Thus, due to the high equipment costs, higher material costs, increased product weight, excessive off-quality, and the likelihood of product returns, only a few companies undertook the manufacture of these modular carpet products.
Over time, the demand for the bonded carpet tiles (e.g., 202) decreased, and tufted broadloom constructions were considered for conversion into a modular product. With tufting equipment, both loop piles and cut piles could be produced, with or without texture, and at greater manufacturing speeds than bonded products. Unfortunately, the tufting process could not support the use of pre-formed fiberglass mats (e.g., 170) as a primary backing material. As the tufting needles (1000) penetrated the fiberglass mat, the glass fibers would break, causing the fiberglass mat to rupture and preventing the yarn (104) from forming stitches on the back side of the fiberglass mat.
Accordingly, for tufted modular products 204, as shown in FIG. 5, a synthetic primary backing substrate 120 was used as the tufting substrate for the yarns 210. It was found that, when the synthetic primary backing substrate 120 was a nonwoven mat of polyester or nylon, the yarns 110 were not securely held during processing. As a result, the yarns in the pile could experience “robbing,” in which one tuft is shortened or robbed by the next tuft, causing unwelcome variations in pile height. More mending of the yarns was required during tufting, which was made more difficult due to the weakness of the nonwoven mat.
Further, pulled yarns (i.e., yarns not securely held by the nonwoven mat) caused voids in the pile face and defects in the backing application. On occasion, the unsecured yarns could be pulled or snagged during the backing application, leading to the defects described above. The weakness of the nonwoven mat led to weak tuft binds in the final floor covering, as the yarn defects prevent adequate penetration of the adhesive pre-coat composition.
It was also observed that the nonwoven mat itself could lose width (shrink) when pulled through production processes, resulting in a condition known as “neck-down.” Finally, even with the problems described above, nonwoven mats are more expensive than “commodity-grade” woven primary substrates.
All of the problems described above with nonwoven primary backing substrates are exaggerated, when the tufting is accomplished using specialty tufting equipment to produce a “graphics tufted” product. In graphics tufting, zigzag stitches and/or multiple “step-over” patterns are employed to obtain color and texture on the face of the floor covering. As a result, graphics tufted textile substrates have two or more yarns stacked on top of each other on the back side of the primary backing substrate, all of the yarns requiring penetration from an adhesive (pre-coat) composition to produce a finished floor covering.
For the reasons described above, manufacturers preferred to use a “commodity-grade” woven primary substrate as the tufting substrate. The most commonly used commodity-grade primary backing substrate was a woven polypropylene material that was designed to hold the yarn stitches tightly during the tufting process. Particularly with graphics tufting, the woven primary backing substrates resulted in a floor covering with greater pattern or design definition, color separation, and texture uniformity than could be achieved with a nonwoven primary backing substrate. Such results were observed because the yarn-holding ability of the woven primary backing substrate permitted more yarns to be located on the face side of the primary backing substrate than on the back side, which not only improved the appearance of the floor covering but also reduced the volume of adhesive composition required to secure the yarns.
This woven polypropylene primary backing substrate 120 was not as thermally stable as the previously used fiberglass backing mat, which led to greater dimensional stability problems (such as curling). Before application of any secondary backing material occurred, it was necessary for the tufted pile substrate (that is, the pile yarns 210 and the primary backing substrate 120) to receive an adhesive coating 132 to secure the yarns 210 in place. The adhesive layer 132 could be made of any polymer type desired by the carpet manufacturer (such as water-based, PVC, hot melts, polyurethanes, and the like). This coating layer 132 was used whether the tufted pile substrate was intended for broadloom or modular carpets. The adhesive layer 132 penetrated into the individual face yarn stitches, both to hold the yarns in position and to prevent the carpet from pilling and/or fuzzing when exposed to foot traffic.
Further shown in FIG. 5, the tufted modular carpet 204 incorporated an “I-beam” reinforcement construction, in which the fiberglass reinforcement mat 175 was positioned between layers of PVC backing layers 160, 165. The fiberglass reinforcement mat 175 was positioned as far as possible from the primary backing substrate 120 supposedly to maximize stability. The PVC backing layer 160 was subsequently secured to the adhesive layer 132.
In the floor covering industry, the adhesive layer (e.g., 132) is referred to as “unitary” if no additional backing layers are to be used and is called a “pre-coat” if additional backing layers are to be applied.
For example, if a broadloom carpet is designed for a direct and permanent gluing to the floor, it could contain only a single adhesive layer on the back side to secure the face yarns. The adhesive layer would then be referred to as a “unitary” coating, signifying that no additional backings are employed. However, this carpet is not stabilized, and the carpet would not perform if not permanently glued to the floor. Predictably, gluing the carpet to the floor makes it very difficult to remove and recycle after its useful life, and removal involves scraping the carpet from the floor.
In most carpet constructions, whether broadloom or modular, the adhesive layer (e.g., 132) functions as a “pre-coat” to which other backing layers may be bonded (as shown in FIG. 5) to prevent the carpet from expanding or contracting during use. The additional backing layers—and the adhesive layer(s) used to bond them together—add weight to the carpet assembly. Specifically, most of the weight in a modular carpet is due to the inclusion of a pre-formed reinforcement layer (e.g., 175) between layers of adhesive backing (e.g, 160, 165), such that the thick polymer layers penetrate and envelop the reinforcement layer.
The curing or cooling of the backing layers 160, 165 requires a long dwell time at high temperature to cure or a long dwell time at ambient temperature to cool, regardless of whether the backing layers 160, 165 are made of PVC, hot-melt compounds, or polyurethane. The curing process necessarily exposes the tufted textile substrate to high temperatures, since lamination of the layers must occur simultaneous with the curing process. Particularly when the primary backing substrate 120 is a woven polypropylene substrate, the heat used to cure the backing layers can cause the synthetic primary backing substrate 120 to shrink, while the polymer backing layers 160, 165 containing the reinforcement layer 175 will not. The differential shrinkage may lead to curling or cupping of the carpet tile and, thus, the carpet tile requires extensive testing prior to shipping.
Although the backing layers 160, 165 are heavy and the resulting product is fairly rigid, the weight of the tile alone is insufficient to overcome any inherent issues with cupping or curling. In fact, the rigidity of the product can prevent the product from being successfully installed on a floor surface if cupping or curling exists, even with the application of installation adhesive between the floor and the carpet product. No amount of adhesive (whether permanent or pressure-sensitive) is sufficient to overcome any inherent cupping or curling in a rigid floor covering. For that reason, modular floor covering that has experienced cupping or curling must be identified as off-quality.
It is known that water-based (or latex) adhesives may be processed at lower temperatures, because curing of the polymer is not required and application of heat is only required for removing water from the adhesive. For this reason and others, most carpet manufacturers prefer to use a water-based adhesive as a pre-coat adhesive layer. Another advantage of latex compositions is that manufacturers can inject air into the latex compositions in a process known as “frothing.” The frothing process reduces the weight of the adhesive applied by replacing a portion of the polymer with air bubbles. The weight volume of air in the latex composition allows lower weights to be obtained, resulting in lower manufacturing and shipping costs. In addition to air, filler materials may be added to latex-based adhesives, further reducing costs. Manufacturers have found also that, when using a frothed composition, it is easier to control the penetration of the water constituent in the adhesive into the yarns. The penetration of the adhesive pre-coat can be varied, depending on (a) the viscosity of the adhesive; (b) the pressure of the adhesive applicator roll against the yarns; and (c) the amount of air included in the adhesive, as well as the stitch rate and size of the yarns.
The adhesive used in the pre-coat layer (e.g., 132) must possess a certain viscosity to effectively penetrate the yarns. It has been found that viscosities of between about 3,000 to about 15,000 centipoise (cps) ensure optimum yarn penetration, such that each fiber within the twisted or air-entangled yarn 210 in the pile is contacted by the adhesive. To date, manufacturers have avoided extremely low viscosity adhesives for several reasons. First, extremely low viscosity adhesives tend to have greater penetration into the yarns, which can result in the adhesive bleeding through to the face side of the carpet. This bleed-through can cause a variety of off-quality issues (such as spikes of adhesive that negatively impact the feel of the carpet and color non-uniformity that negatively impacts the appearance of the carpet). Secondly, the adhesives used for carpet applications contain fillers, such as calcium carbonate (CaCO2) and/or alumina tri-hydrate, which can fall out or settle to the bottom of storage vessels in manufacturing, causing variations in application. This problem is even more pronounced in low viscosity adhesives, which lack the inherent thickness to keep these fillers in solution.
The preferred viscosity of the pre-coat adhesive depends on the application method to be used. Most manufacturers use an applicator roll 1006 (sometimes called a “doctor roll”) over a plate and allow the tufted textile substrate (120, 210) to be pulled under the roll 1006, as shown in FIG. 6. A puddle of the adhesive 132 forms near the roll 1006, such that a puddle rides on the back side of the substrate. As the tufted textile substrate is pulled under the applicator roll 1006, the hydraulic force increases as the puddle is pulled under the roll, and the contact between the roll 1006 and the back side of the tufted textile substrate 120 forces the adhesive 132 into the yarns 210. The control of the viscosity of the pre-coat adhesive composition is important to ensure the proper penetration of the adhesive into the yarns 210, as discussed above.
The next evolutionary step in the production of modular carpets was the replacement of the PVC backing layer with a hot-melt backing formulation. Hot-melt adhesives (or hot-melt polymers) are thermoplastics applied in molten form, which solidify on cooling to form a hard, durable backing layer. Examples of hot-melt adhesives include, but are not limited to, polyesters, polyamides, polyolefins, polyethylenes, atactic polypropylene, and asphalt-based compounds. Hot-melt polymers are known for their resistance to water and/or solvents.
Initially, manufacturers attempted to create a floor covering (not illustrated) with a hot-melt polymer backing and without a pre-formed reinforcement mat. The floor covering would lie flat without curling or cupping. However, when cut into tiles, the residual force applied to the synthetic primary backing during the hot-melt application caused the tile to lose dimension and to become non-uniformly sized as compared with other tiles. Another problem with the non-reinforced hot-melt floor covering was the “creep” or “cold flow” within the hot-melt layer. That is, forces exerted on the floor covering, such as from office chairs and foot traffic, caused the hot melt backing to expand, leading to tile “growth.”
Again, manufacturers turned to the “I-beam” reinforcement construction used previously. The idea of a “free lay” modular carpet installation faded, as even the most stable carpet tiles required at least a grid system of pressure sensitive adhesive to prevent the tiles from moving and from becoming misaligned during installation and use. The adhesive grid also helped to prevent gaps from forming between adjacent carpet tiles.
Facing on-going challenges with tile stability and with adhesive application in the aforementioned grid pattern, installers began applying a full coverage of the flooring adhesive. This full coverage approach was quicker to accomplish than the grid application and became the standard method of installation, which was eventually endorsed by the modular carpet manufacturers. Modular tiles with their heavy backing layers and “I-beam” reinforcement layer remained stiff. The stiffness of the tile had the potential to exert a tremendous amount of force, if not dimensionally stable. As a result, even a full coverage of glue could not hold the tile flat, if it had an inherent tendency to cup or curl.
In addition to overcoming the stability problems described above, modular carpet manufacturers faced other challenges in the manufacturing process:
(1) Thickness and weight variation (side-to-side and/or end-to-end) could result from the uneven application of multiple thick polymer layers. Because tiles cut from one area of processed carpet were routinely installed adjacent tiles from other areas of the processed carpet, consistency in thickness and weight was required to create an installed floor covering of uniform height.
(2) As with broadloom carpets having one or more secondary backing layers, delamination could result from incomplete adhesion between the various layers in the modular tile. Each interface between layers was susceptible to delamination.
(3) Excessive weight was required, since the pre-formed reinforcement layer was positioned between, and penetrated by, polymer coatings. Insufficient penetration had the potential to lead to delamination (as described above). Moreover, because the pre-formed reinforcement layer was fiberglass, complete embedding was necessary to prevent irritation caused by the exposed fiberglass. For modular floor coverings employing an “I-beam” construction, sufficient backing coating layers were needed to ensure the proper spacing of the reinforcement layer.
(4) Creep and cold flow, as discussed above, were experienced in modular tiles having a hot-melt backing system. It was observed that thick coatings tended to expand under high loadings, such as rolling chairs or heavy foot traffic. Conversely, backings made from PVC tended to shrink due to plasticizer migration and exhibited problems with volatile organic compounds (VOCs) and smoke generation.
(5) Recycling of the multiple backing layers, yarns, and the pre-formed reinforcement layer was almost impossible, due to the bonding of the layers and their disparate materials.
(6) Cost was also a significant challenge. In addition to the material costs of the backings, manufacturers faced expensive processing steps, slow production speeds, and high off-quality. As a result, the modular carpet product could cost as much as 50% more than broadloom to produce, which limited its practical use to only specialized commercial installations.
In addition to the problems described above, modular floor coverings had another significant marketing disadvantage, when compared to broadloom carpets, which was the comfort level of the modular floor covering. To address the comfort issue, a cushion layer 180 was incorporated into a cushion-back modular floor covering 206, as shown in FIG. 7. The backing layer 160 was made of a hot-melt polymer compound. The hot-melt compound was applied to the tufted textile backing in a molten state and, upon cooling, achieved lamination of the tufted textile backing to the reinforcement layers. In contrast, when PVC was used as the polymer backing material, it was necessary to pass heat through both the tufted textile substrate and the cushion layer 180 to cure the PVC, which was impractical.
A first “I-beam” construction was created between the primary backing substrate 120 and a first pre-formed reinforcement mat 170. The cushion layer 180 was adhered to the first pre-formed reinforcement mat 170. To protect the cushion layer 180 from tears or abrasion, another pre-formed synthetic reinforcement mat 175 was added, thereby creating a second “I-beam” construction between the reinforcement mats 170, 175. The location of the reinforcement mats 170, 175 was even more critical in accomplishing the desired stability of the floor covering 206. If the mats 170, 175 were misplaced, the processing of the floor covering 206 could cause too much heat on one side of the floor covering 206, resulting in cupping or curling of the finished product. As a result, manufacturers faced considerable issues with off-quality and waste, and returns were common.
Cushion-back tiles 206 experienced many of the same problems described above for “hard-back” tiles and, in some instances, experienced even more problems, including:
(1) Thickness variation and weight were significantly more difficult to control than with hard-back tiles, due to the amount of air incorporated in the cushion layer (180), the consistency with which the cushion layer was applied, and the moisture levels in the foam comprising the cushion layer.
(2) Delamination was a greater problem, since the cushion layer (180) had much less internal strength alone or when joined to another layer and since the polymer used in making the cushion layer was incompatible with most other polymers. Thus, the lamination strength was weaker for the cushion-back modular floor covering 206, as compared with the hard-back floor covering.
(3) Achieving dimensional stability of the cushion-back floor covering 206 was a challenge, due to the incorporation of two pre-formed reinforcement layers 170, 175 in a double “I-beam” assembly. The positioning of each layer 170, 175, bearing in mind its potential for shrinkage, required precise control to produce the desired dimensional stability.
(4) Recycling of cushion-back floor coverings 206 was even more difficult than hard-back floor coverings, because of the inclusion of another layer of disparate polymer material.
(5) Costs associated with producing a cushion-back floor covering 206 were even higher than those seen with a hard-back floor covering. The cushion layer 180 was typically a reactive polyurethane material, which is expensive and is difficult to apply (due to the previously mentioned spacing requirements and expensive specialty equipment required). The cushion layer 180 and its protective reinforcement layer 175, and the associated processing steps, thus contributed to the increased material and production costs for the cushion-back product.
Efforts to dye or color the modular floor coverings 206 with liquid dyes led to more challenges with stability. The dyeing process exposed the floor covering 206 to steam, saturation with water, and excessive heat to dry. These conditions made proper placement of the reinforcement layers 170, 175 in the “I-beam” construction even more critical to control shrinkage of the synthetic backing substrates.
Over time, manufacturers sought to apply the components of modular construction to broadloom carpets with the objective of facilitating rolling traffic across the carpet. By using a broadloom product, manufacturers tried to eliminate the risk of water penetration through the seams and the textile face of a modular floor covering installation.
An exemplary broadloom carpet is illustrated as floor covering 208 in FIG. 8. A tufted textile substrate, having a yarn pile 210 tufted through a primary backing substrate 120, was used as the face of the floor covering 208. The stitch portions of the yarns 210 were secured by a pre-coat adhesive application 132. A polymer backing 160 was applied to form the backing of the floor covering 208.
Because broadloom carpets are shipped in rolls, the material of choice for the polymer backing 160 was PVC, which was more flexible than the stiff hot-melt adhesives and/or bulky cushion layers used in modular products. However, because this polymer backing was heavy, the resulting product was difficult to ship and to install, leading to a reduction in shipped widths from 12 to 15 linear feet to only 6 linear feet. The pre-formed reinforcement layer used in modular constructions (e.g., 170) was omitted to promote the flexibility of the carpet, which destroyed the stabilizing “I-beam” construction. This removal of the “I-beam” construction led to stability problems in the finished carpet, which could only be counteracted by permanent adhesion to the floor.
As discussed above, PVC polymer backings create a hard backing surface. To achieve the comfort level expected from broadloom carpets, some PVC-backed broadloom floor coverings 208 were provided with an additional cushion layer attached to the PVC backing layer 160 (not shown). In these cases, there were only a limited number of cushion options available from the manufacturer, and, with the addition of another layer, manufacturers faced many of the same stability challenges and off-quality issues described above.
In other cases, secondary-backed broadloom floor coverings 208 were glued over a specialized cushion pad that was glued to the floor using a “double-stick” technique. The specialized cushion pads were designed to minimize adhesive penetration into the cushion. The double-stick approach allowed the consumer to have more options over the thickness of the cushion and, thus, the comfort level of the floor covering. However, this installation method was expensive and time-consuming. Moreover, the installation was permanent and difficult to remove. As a result, this approach was typically restricted to commercial settings with larger open spaces, where stretching the broadloom floor covering was impractical due to room size.
As is evident from the discussion above, floor covering manufacturers have encountered substantial challenges in designing a floor covering that is stable in production and installation. These challenges have led to a large number of specialized carpet backing constructions and necessary processing equipment. Thus, a universal reinforcing backing layer, such as that described herein, which could be applied to both broadloom and modular floor coverings, would represent a significant advance in the floor covering industry.
Another consideration left wholly unsatisfied by existing floor coverings is the ability to recycle the floor covering. Because the floor coverings described above often included many layers of different polymer types, separating the floor coverings into useful streams of the component materials has been virtually impossible. For this reason, the majority (approximately 95%) of floor coverings disposed of annually in the United States are landfilled or incinerated.
One attempt at recycling carpet that was tried was grinding the entire floor covering and reforming the ground components into a new layer, either with compression or partial melting of the thermoplastic components and encapsulation of the thermoset components. This new layer of recycled materials was then embedded within another backing compound, such as the backing layer, to add weight to a virgin modular carpet. Even after the purchase of expensive equipment to facilitate material reuse, manufacturers experienced difficulties in controlling the assembly and realized high levels of off-quality product.
Therefore, an improved backing layer of lower cost that would facilitate recycling, while maintaining the requisite dimensional stability, would also represent an advance in the floor covering art. Such a backing layer is provided herein, as are methods of manufacturing, installing, and recycling the present floor coverings including the inventive backing layer.